2-[vinyl-dicarboxylic acid ester]-3-amino-1, 2, 4-triazoles as stabilizers for photographic silver-halide emulsions



2\ l \\\\\\\\\\\\\\\\\\\\\\\\\HV Sept. 141948. N. HElMBAcH ETAL 2,449,226 Y 2- w L-DICARBOXYLIG ACID E E -3 AMINO1,2,4TRI AS BILIZERS FOR PHOTOGRA C SILVER-HALIDE EMUL NS Y Filed oct. 22, 194s SUPPORT SUP/DOE' 7' IN VEN TOR. NEWTON HE/MBACH WAL TEP KELLY J/a Patented Sept. 14, 1948 2- [VINYL-DICARBOXYLIC ACID ESTER] -3- AMINO-1,2,4TRIAZOLES ASI STABILIZERS FOR i PHOTOGRAPHIC -SILVER-HALIDE EMULSIONS Newton Heimbach and Walter Kelly, Jr., Binghamton, N. Y., assignors to General Aniline &

Film Corporation, New York, N. Y., a corporation of Delaware Application October 22, 1946, Serial No. 104,934

This invention relates to 2-[vinyl-dicarboxylic acid ester]-3amno-1,2,4triazoles, to a method for their preparation, and to photographic silverhalide emulsions.

from the following specication.

resulting condensation product isz'characterized i1 claims. (c1. sis-'1) by a structure corresponding to the following general formula:

oo halide emulsions containing the same. (L R It is known in the art that light-sensitive emul- 5 C CH N N\* sions, such as gelatin silver-halide emulsions, /C'Rl hfavte a dtecided tendency to fog, The fog maybe cooR HzN-C=N o wo ypes, namely, yellow fog and chemical .e (gray) fog. The yellow fog, sometimes referred gllmbt analyregpaldg to as color fog or dichroic fog, is essentially a lk l f th 1 R n colloidal deposit of silver the c l t 't d or an a y group o e same Va-ue as n 0 or 71.93511 Y an The method for the preparation of 2-[v1ny-lgeneriu appearajn of Whmh are detefmllfq by dicarboxylic acid ester]-3-amino-l,2,4-triazoles the mlnute particle size and degree of subdivision. Consists of condens-ing 1 m01 of an alkoxymethyl- The fog is chiefly yellow in color and ismostapene mamme ester of the following general parent in the lighter portions of a negative. The formula. l i color may vary, however, and the colloidal silver particles may, for example, appear gren bym? COORI flectedlight and yellow or red by transmitted C=CH-0R= light. The so-called chemical fog, or .grayyfog on 00PM the other hand' 1S the more Common and-1s 20 wherein R2 is of the same value as R, with 1 mol formed in a number of ways. f It maybe caused of 3 amin0 1,2,4-1;riaz01e 0f the following general by premature exposure, by excessive ripening of frmula; l the emulsions, or by the storage of the hlm, pari ticularly at high temperatures or `forunusuallv HNN long periods of time. l C-R It is an object of the present invention topro- H2N-C=N 1 vide 2- [vinyl-dicarboxylic yacid ester] -S-amino- Wheein R3 is of the same vaine as RL 1,2,4-triazoles useful as stabilizers for` silver- Suitable alkoxymethylene mamme esteis are,

30 for example, methyl methoxymethylene malo- Another object of this invention isto provide a nate, ethy1 methoxymethylene malonate, methyl plfOCeSS 0f Preparing Such 2-[Viny1-dicarboXYlC ethoxymethylene malonate, ethyl ethoxymethylacid ester] hammo12f4t1`a'z0les ene malonate, propyl ethoxymethylene malonate,

A further Object S t0 Provide gewinn-11031 ethyl propoxymethylene malonate, methyl buboxylic acid ester]3amino1,2.,4-triazoles as 35 toxymethylene malonate, and the like. stabilizers or fog inhibiting agents'which tend to As Suitable 3amno1,2,4triazoles may be prevent the formation of chemical fog inlightmentioned, 3-amino-1,2,4triazole, y3amino-5 sensitive silver-halide emulsions. i methyl-1,2,4-triazole, 3-amino-5-ethyl-1,IZ,4-tria A still further object is to provide 2-[vinylzole, ,3-amino-5-propyl-l,2,4ftriazole, l-aminodicarboxylic acid ester]3-amino-1,2,ltriazoles `40 `ti-isopropyl-l,2,i-triazole, and the like, as stabilizers or anti-iogging` agents` for lightv"`1`hecondensation between the alkoxymethylene sensitive silver-halide emulsions,- which `do, not malonic ester and the 3amino-1,2`,v4triazole is lower the sensitivity of the emulsion, and which 4,carried out by allowing the reaction components increase its stability. y I to stand at room temperature with occasional Still further objects and advantages willfappear `15 shaking, in the presence of an alcohol-water Y lmixture,.for a period of time ranging from 1 to We have found that the above objects are ac- 3 days.` The product either precipitates, or is recomplished by condensing an alkoxymethy-lene moved by evaporation `of the solvent mixture at malonic ester with a 3-amino1,2,4triazole. The room temperature. l t n The final product is recrystallized fromV either amino-1,2,4triazole are well-known to the art f and the method for their preparation need not be described herein.

Specific compounds which have been prepared in accordance with the above procedures, with their formulas, are as follows:

2-[, -dcarbomethoxyvinyll-B-amino-l,2,4-triazole The following examples are intended toillustrate the preparation of the compounds disclosed above. It will be appreciated that the conditions of reacti-ons, e. g., time of reaction and temperature, may be waried, and that the supplementary process of purication may be resorted to whereever found desirable.

Example I To a mixture of V30 cc. of ethanola'nd 15 cc. of water, 0.1 mol (8.4 grams) of l3amino1,2,4- triazole and 0.1 mol (21.6 grams) of ethyl ethoxymethylene malonate were added and the mixture allowed to stand at room temperature fory 2` days withoccasional shaking. The solvent of the reaction mixture was evaporated at room temperature. A thick colorless oil was obtained which crystallized slowly in the course of a week. The oil was diluted with ether and the crystalline product filtered off and recrystallized from boiling water.

Example II C o o 02H5 To a mixture of 15 cc. of ethanol and 3 cc. of water,. 0.05v mol (4.9 grams) of 3-amino-5- methyl-1,2,4-triazole and 0.05 mol (10.8 grams) of ethyl ethoxymethylene malonate were added and the mixture allowed to stand at room temperature for 2 days. The solvent of the reaction mixture was evaporated oi at room temperature and the product dissolved in ethanol, ltered, and recrystallized from ethanol.

Example III rI 'o a. mixture of 20 cc. of ethanol and 5 cc. of water, 0.05. mol (4.2 grams) of 3amino-1,2,4- triazole and 0.05 mol (9.4 grams) oi methyl ethoxymethylene malonate were added and the mixture allowed to stand at room temperature for 1 day. The white product which slowly crystallized out Was filtered, Washed with ether, and recrystallized from boiling Water.

In the preparation of emulsions containing the stabilizers as abo-ve prepared, a solution of the stabilizer in a suitablesolvent, such as alcohol or an alcohol-watermixture, adjusted to a neutral or slightly alkaline pH, i. e., pH 7.5 to 10, is made up and the solution mixed with thel emulsion at any point during its preparation, but preferably during ripening or just prior to coating in concentrations varying from 25 mg. to 500 mg. per liter of emulsion. The actual concentration employed :will depend upon the type of emulsion used, and may vary somewhat with the particular compound employed. Y

yThe method of testing the stabilizers employed in the following examples consists of coating two lm strips, such as cellulose acetate, withV the same emulsion, one with and one without stabilizer, storing the emulsions in an incubator for six days at 50 C., then exposing, developing, xing, and washing the same under standard conditions. The fog density or blackening produced in the unexposed areas in the two emulsions is then measured in a transmission denstometer of standard type.

The following examples will serve to illustrate certain ways in which the Z-[vinyl-dicarboxylic vacid ester]-3-amino-1,2,4-triazoles, of our invention, are applied as stabilizers for silver-halide emulsions, but are not to be construed as limiting the invention. 1

Ezvample I V A photographic film coated with an ordinaryV gelatin-bromoiodide emulsion of normal speed and contrast on development under standard conditions, after incubation for six days at 50 C., gave a fog of 0.28 density. Another iilm coated with the same emulsion containing an addition of mg. of the compound of Example I per 1000 cc. of emulsion, equivalent to .about 50 grams of silver-halide, and developed under the same conditions, after the same incubation, gave a fog o only 0.06 density. y

f Example' IV was Example V repeated with the exception that an equivalent quantity of the compound of Example II was substituted for the compound of Example I. The results obtained were almost identical with those obtained in Example IV.

Example VI Example IV was again repeated with the exception that '75 mgs. of the compound of Example III were substituted for 100 mgs. of the compound `oi Example I. After incubation and development,

also be employed in non-sensitized emulsions and X-ray emulsions. If used with sensitizing dyes they may be added to the emulsion beforeor after the dyes are added. The dispersing agents for the silver-halides may be gelatin o-r other colloid such as water-soluble cellulose derivatives, e. g., hydroxy ethyl cellulose, methyl cellulose, carboxy- Oxy-cellulose, low acetyl value cellulose acetate, and the like. The stabilizers may also be employed in gelatin or other colloid, such as polyamides or a mixture of gelatin with a polyamide as described in United States Patent 2,289,775; polyvinyl alcohol and jelling compound as described in United States Patent 2,249,537; polyvinyl acetaldehyde acetal resins and partially hydrolyzed acetate resins described in United States Patents 1,939,422 and 2,036,092; cellulose derivatives, e. g., cellulose nitrate, cellulose acetate, and the lower fatty acid esters of cellulose including simple and mixed esters and ethers of cellulose, and the like, as an under or overcoat for the emulsion, or as a backing layer for the support. Moreover, they may be incorporated the support for the sensitive emulsion layer or in an intermediate layer between the sensitive emulsion layer and the support, such as the baryta coating commonly used in photographic papers, or they may be incorporated in a protective layer coated upon the emulsion surface. Again, the otherwise nished photographic material may be bathed in an alcohol or alcohol-water solution containing the stabilizer.

In the accompanying drawing the various iigures are enlarged section views of photographic materials having anti-fogging layers made according to our invention.

As shown in Figure 1, the support l, which may be of any suitable material such-as glass, cellulose ester, synthetic resin, or paper, is provided with an anti-fogging layer 3, containingr one of the Z-[Vinyl-dicarboxylio acid esterl-3-amino- 1,2,4-triazoles referred to above. The lightsensitive emulsion layer 2 is attached to the antifogging layer 3.

Figure 2 illustrates a similar material in which the support l is coated with a light-sensitive emulsion layer 2, and on the latter side there is provided an anti-fogging layer 3 containing one of said 2- [vinyl-dicarboxylic acid ester] -S-amino- 1,2,4-triazoles.

Figure 3 `illustrates a `iilm `or plate,- of" which the support I bears on one `side the light-sensi'- tive emulsion layer 2, and on the other side an anti-fogging layer 3 containing one of said 2-[vinyl-dicarboxylic acid esterl`3amino-1,2,4- triazoles.

Figure 4 illustrates a lm, plate, or paper of which the support I is provided with the lightsensitive emulsion layer 2 containingv as an antifogging layer one of said 2- [vinyl-dicarboxylic acid ester]-3-amino-1,2,4-triazoles.

Since the presence of `thesenew compounds tends to prevent chemical ,fog whether they are incorporated directly into the emulsion, added to a separate surface or substratum layer, it 'is understood that the term photographic material as employed herein and in the appended claims, is used in a generic sense to include each of these possible applications.

Various modications of this" invention will occur to persons skilled in theart and it `is,.thereof the general formula:

wherein R is an alkyl group and R1 is a member selected from the class consisting of hydrogen and alkyl groups. l- 1 2. A photographic material comprising a base and a light sensitive silver-halide emulsion carried thereby, said photographic material containing, in fog inhibiting amount, a compound of the formula: l

3. A photographic material comprising a -base and a light sensitive silver-halide emulsion carried thereby, said photographic material containing, in fog inhibiting amount, a compound of the formula:

4. A photographic material comprising a base and a light sensitive silver-halide emulsion carried thereby, said photographic-materia1 containing, in fog inhibiting amount, a compound of the formula:

5. A photographic material comprising a base and a light-sensitive silver-halide emulsion con- 7 taining, in fog inhibiting amount,'alcompound of the general formula:

oooR

COOCsHi HnN-C= N/ 7. A photographic material comprising a. base and av light-sensitive silver-halide emulsion containing, in fog inhibiting amount, a compound 0000111. EIN-ieri 8. A photographic material comprising a base and a. light-sensitive silver-halide emulsion containing, in fog inhibiting amount, a compound of the formula:

8 9. A photographic gelatino silver-halide emulsion containing from aboutv25 mg. to about 500 mg. per liter ofemulsion of a compound of the formula:

10. A photographic gelatino silver-halide emu1- sion containing from about 25 mg. to about 500 mg. per liter of emulsion of a compound of the formula:

([1 o o c 21ers o=oH NN Y o-oH coocaHs H2N-o=1\i 11. A photographic gelatine silver-halide emulsion containing from about mg. to about 500 mg. per liter of emulsion of a compound of the formula:

o o o c H3 25 o=oH N-N /oH o con, H2N-o=N NEWTON HEIMBACH.

WALTER KELLY, JR.

REFERENCES CITED The `ollowing references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Matthies et al May 13, 1930 Number 

